Petrography and provenance of sandstone and studies of shale of kuldana formation kalamula and khursheedabad area kahuta azad kashmir
Journal: Earth Science Malaysia (ESMY)
Author: Ahmer Bilal, Muhammad Sabir Khan
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Rocks exposed in the study area are Kuldana Formation which is comprised of variegated color shale and sandstone. The model data of Kuldana sandstone exhibit average quartz 35%, feldspars 3%, rock fragments 20% and heavy minerals. The quartz grains are of igneous and metamorphic origin. Mineral quartz, feldspar, and rock fragments in the sandstone suggested an acidic plutonic and metamorphic provenance. Rock fragments are of sedimentary, volcanic and metamorphic rocks. The sedimentary grains include limestone, dolomite, quartzite, sandstone and siltstone. The volcanic rock fragments are of fine grained basalts. The metamorphic rock fragments are of slates and schists.
Heavy minerals include tourmaline, zircon, garnet, epidote, sphene and apatite. Hematite and calcite are the dominating cementing material with minor chlorite. The sandstone is classified as graywacke. The low modal proportion of quartz and high content of rock fragments indicates low degree of mineralogical maturity of the sandstone. The poor degree of sorting, angular to sub-angular framework constituents and abundance of matrix suggested that sandstone is texturally immature. The sutured quartz grains contacts, alteration of plagioclase to clay minerals and deformed muscovite indicate diagenetic changes in the sandstone at depth under pressure. The XRD analysis of shale show minerals chlorite thuringite, orthoclase, corrensite mica, illite, albite, smectite, saponite, montmorillonite, goethite, kaolinite, vermiculite, aragonite, calcite, quartz, siderite, muscovite, hematite, pyrite and dolomite. Recalculated value of quartz, clay and carbonates on ternary diagram shows that the clays are argillaceous. Quartz, orthoclase, albite and muscovite in the shale suggest acidic plutonic and metamorphic provenance.